The United States and Japan will step up their defence cooperation to deal with the threat from nuclear-armed North Korea as tensions in East Asia remain high, officials from the two allies said on Thursday.

NSW pedophile sentence 'inadequate': DPP

Confessed pedophile Maurie Van Ryn will have to wait to see if his seven-year jail sentence for crimes against children is upheld or even increased.

The former Bega Cheese boss is facing the prospect of even more time in jail for his crimes against children after the Director of Public Prosecutions (DPP) declared seven years to be "manifestly inadequate".

The NSW Court of Criminal Appeal (CCA) is re-examining the jail term handed to Van Ryn in September for abusing nine boys and girls between 2003 and 2014.

Van Ryn's lawyer Stephen Odgers SC told the court on Wednesday that his client had been a danger to the community for most of his life but that didn't mean the sentence was inadequate.

He said the 59-year-old had been taking chemical castration medication "religiously" since 2014.

The court heard this made Van Ryn's rehabilitation prospects strong, and allowed sentencing judge Clive Jeffreys to give the principle of deterrence less weight in sentencing.

"I'm not asking for sympathy for him, but he's got a condition. He's obviously not choosing to be a pedophile," Mr Odgers said.